They aren’t brothers, but the main character is crazy here you go http://www.mangago.me/read-manga/hogu_hagyeongsu/?av=2
u can try reading:
http://www.mangago.me/read-manga/banquet_box/
http://www.mangago.me/read-manga/lookism/
http://www.mangago.me/read-manga/white_angels_have_no_wings/
http://www.mangago.me/read-manga/the_queen_a_silent_classroom/
and "killing stalking" but i guess that u already know about it...
Are there any stories that are similar like 'An uncomfortable truth' or 'Save Me' or 'Bastard', etc??